Three-dimensional structure electrode and electrochemical element including same

Abstract

The present invention relates to a three-dimensional structure electrode, a method for manufacturing same, and an electrochemical element including the electrode. The present invention is characterized by comprising: (a) an upper conductive layer and a lower conductive layer which have a structure constituting an assembly within which a conductive material and a porous nonwoven fabric including a plurality of polymeric fibers are three-dimensionally connected in an irregular and continuous manner, thereby forming a mutually connected porous structure; and (b) an active material layer forming the same assembly structure as the conductive layers and forming a three-dimensionally filled structure in which electrode active material particles are uniformly filled inside the mutually connected porous structure formed in the assembly structure, wherein the active material layer is formed between the upper conductive layer and the lower conductive layer.

The invention claimed is: 
     
       1. A method for manufacturing an electrode having a three-dimensional structure, the method comprising:
 (a) preparing a polymer solution including a polymer and a solvent; 
 (b) preparing a first colloidal solution including a conductive material, a dispersant, and a dispersion medium; 
 (c) preparing a second colloidal solution including the conductive material, the dispersant, the dispersion medium, and active material particles; 
 (d) preparing three-dimensional structure fibers using the polymer solution, the first colloidal solution, and the second colloidal solution; and 
 (e) compressing the three-dimensional structure fibers, 
 wherein step (d) comprises: 
 simultaneously spinning the polymer solution and a first portion of the first colloidal solution to prepare a lower conductive layer; 
 simultaneously spinning the polymer solution and the second colloidal solution on top of the lower conductive layer to prepare an active material layer; and 
 simultaneously spinning the polymer solution and a second portion of the first colloidal solution on top of the active material layer to prepare an upper conductive layer, 
 wherein the upper conductive layer and the lower conductive layer each have a porosity that is smaller than a porosity of the active material layer. 
 
     
     
       2. The method of  claim 1 , wherein step (d) is performed by using one method selected from the group consisting of: double electrospinning, double electrospray, double spray, and combinations thereof. 
     
     
       3. The method of  claim 1 , wherein during step (d), a spinning rate of the polymer solution is 2 to 15 μl/min, and
 wherein a spinning rate of the first and second portions of the first colloidal solution and the second colloidal solution is 30 to 300 μl/min. 
 
     
     
       4. The method of  claim 1 , wherein the first colloidal solution includes 0.1 to 50% by weight of the conductive material based on a total weight of the first colloidal solution. 
     
     
       5. The method of  claim 1 , wherein the polymer solution includes 5 to 30% by weight of the polymer based on a total weight of the polymer solution. 
     
     
       6. The method of  claim 1 , wherein step (c) comprises:
 injecting the conductive material into the active material particles to prepare a mixed powder; 
 grinding the mixed powder to obtain a composite of the active material particles and the conductive material; and 
 dispersing the composite within the dispersion medium to prepare the second colloidal solution. 
 
     
     
       7. The method of  claim 1 , wherein step (b) includes dispersing the conductive material within the dispersion medium to prepare the first colloidal solution.